aton.c

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/*
 * aton.c
 *
 * Copyright (c) 2001 Dug Song <dugsong@monkey.org>
 *
 * $Id: aton.c,v 1.3 2002/10/14 15:42:10 dugsong Exp $
 */

#include "config.h"

#include <sys/types.h>

#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "dnet.h"
#include "aton.h"

int
type_aton(char *string, uint16_t *type)
{
        u_int i;

        if (strcmp(string, "ip") == 0)
                *type = htons(ETH_TYPE_IP);
        else if (strcmp(string, "arp") == 0)
                *type = htons(ETH_TYPE_ARP);
        else {
                if (sscanf(string, "%i", &i) != 1 || i > 0xffff)
                        return (-1);
                *type = htons(i & 0xffff);
        }
        return (0);
}

int
op_aton(char *string, uint16_t *op)
{
        u_int i;

        if (strncasecmp(string, "req", 3) == 0)
                *op = htons(ARP_OP_REQUEST);
        else if (strncasecmp(string, "rep", 3) == 0)
                *op = htons(ARP_OP_REPLY);
        else if (strncasecmp(string, "revreq", 6) == 0)
                *op = htons(ARP_OP_REVREQUEST);
        else if (strncasecmp(string, "revrep", 6) == 0)
                *op = htons(ARP_OP_REVREPLY);
        else {
                if (sscanf(string, "%i", &i) != 1 || i > 0xffff)
                        return (-1);
                *op = htons(i & 0xffff);
        }
        return (0);
}

int
proto_aton(char *string, uint8_t *proto)
{
        struct protoent *pp;
        u_int i;
        
        if ((pp = getprotobyname(string)) != NULL)
                *proto = pp->p_proto;
        else {
                if (sscanf(string, "%i", &i) != 1 || i > 0xff)
                        return (-1);
                *proto = i & 0xff;
        }
        return (0);
}

int
off_aton(char *string, uint16_t *off)
{
        int i;
        char *p;

        if (strncmp(string, "0x", 2) == 0) {
                if (sscanf(string, "%i", &i) != 1 || i > IP_OFFMASK)
                        return (-1);
                *off = htons(i);
        } else {
                i = strtol(string, &p, 10);
                if (*string == '\0' || (*p != '\0' && *p != '+') ||
                    i > IP_OFFMASK)
                        return (-1);
                *off = htons(((*p == '+') ? IP_MF : 0) | (i >> 3));
        }
        return (0);
}

int
port_aton(char *string, uint16_t *port)
{
        struct servent *sp;
        u_int i;
        
        /* XXX */
        if ((sp = getservbyname(string, "tcp")) != NULL) {
                *port = sp->s_port;
        } else if ((sp = getservbyname(string, "udp")) != NULL) {
                *port = sp->s_port;
        } else {
                if (sscanf(string, "%i", &i) != 1 || i > 0xffff)
                        return (-1);
                *port = htons(i & 0xffff);
        }
        return (0);
}

int
seq_aton(char *string, uint32_t *seq)
{
        char *p;
        
        *seq = strtoul(string, &p, 10);
        if (*string == '\0' || *p != '\0')
                return (-1);

        *seq = htonl(*seq);
        return (0);
}

int
flags_aton(char *string, uint8_t *flags)
{
        char *p;
        u_int i;

        *flags = 0;
        
        if (strncmp(string, "0x", 2) == 0) {
                if (sscanf(string, "%i", &i) != 1 || i > 0xff)
                        return (-1);
                *flags = i & 0xff;
                
                return (0);
        }
        for (p = string; *p != '\0'; p++) {
                switch (*p) {
                case 'S':
                        *flags |= TH_SYN;
                        break;
                case 'A':
                        *flags |= TH_ACK;
                        break;
                case 'F':
                        *flags |= TH_FIN;
                        break;
                case 'R':
                        *flags |= TH_RST;
                        break;
                case 'P':
                        *flags |= TH_PUSH;
                        break;
                case 'U':
                        *flags |= TH_URG;
                        break;
                default:
                        return (-1);
                }
        }
        return (0);
}

static u_char
hex2num(char ch, char cl)
{
        ch = tolower(ch), cl = tolower(cl);
        
        if (ch >= '0' && ch <= '9')
                ch -= '0';
        else if (ch >= 'a' && ch <= 'f')
                ch -= 'a' - 10;
        else
                return (0);
        
        if (cl >= '0' && cl <= '9')
                cl -= '0';
        else if (cl >= 'a' && cl <= 'f')
                cl -= 'a' - 10;
        else
                return (0);
        
        return ((u_char)((ch << 4) | cl));
}

int
fmt_aton(char *string, u_char *buf)
{
        u_char *u;
        char *p;

        for (u = buf, p = string; *p != '\0'; p++) {
                if (*p != '\\') {
                        *u++ = *p;
                        continue;
                }
                if (*++p == '\0')
                        break;

                if (*p == '\\')         *u++ = '\\';
                else if (*p == '\'')    *u++ = '\'';
                else if (*p == '"')     *u++ = '"';
                else if (*p == 'a')     *u++ = '\a';
                else if (*p == 'b')     *u++ = '\b';
                else if (*p == 'e')     *u++ = 033;
                else if (*p == 'f')     *u++ = '\f';
                else if (*p == 'n')     *u++ = '\n';
                else if (*p == 'r')     *u++ = '\r';
                else if (*p == 't')     *u++ = '\t';
                else if (*p == 'v')     *u++ = '\v';
                else if (*p == 'x' && p[1] != '\0' && p[2] != '\0') {
                        *u++ = hex2num(p[1], p[2]);
                        p += 2;
                } else
                        return (-1);
        }
        return (u - buf);
}

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